A road-vehicle communication system including a roadside apparatus and a vehicle-mounted device for two-way radio communication between the roadside apparatus and the vehicle-mounted device has been known. The road-vehicle communication system adopts a short range communication system called DSRC (Dedicated Short Range Communication) has been adopted.
It has been considered to distribute regional information (e.g., information on or advertisement for the neighboring shops and medical institutions) from the roadside apparatus to the vehicle-mounted device via the DSRC. The regional information transmitted from the roadside apparatus is saved in the vehicle-mounted device so that it can be reproduced by the vehicle-mounted device even when the vehicle-mounted device cannot communicate with the roadside apparatus (for example, Patent Document 1.)    Patent Document 1: Japanese Patent Application Laid-Open No. 2007-109032